The present invention relates generally to communication networks, and more specifically, to a method and system for finding network neighbor information.
Communication in a computer network involves the exchange of data between two or more entities interconnected by communication links and subnetworks. Communication between computers within the network is made possible with the use of communication protocols, which govern how computers exchange information over a network. In order for proper operation of the protocols, it is important that the devices in the network are properly interconnected so that error free communication can occur across the network.
SONET and SDH are a set of related standards for synchronous data transmission over fiber optic networks. SONET is short for Synchronous Optical Network and SDH is an acronym for Synchronous Digital Hierarchy. A SONET system consists of switches, multiplexers, and repeaters, all connected by fiber. The connection between a source and destination is called a path. The Bellcore GR-253 standard defines SONET, which uses a layered architecture of Path, Line, and Section Overhead (POH, LOH, and SOH). The section, line, and path overheads contain a profusion of bytes used for operations, administration, maintenance, and provisioning (OAM&P).
Switches and other components within the SONET/SDH system are configured to have multiple cable connections (e.g., MGX8850 Multiservice Wide-Area Edge Switch, available from Cisco Systems Inc.). It is important that all of the cables hook up to the correct node, slot, backcard (bay), and line. Since there are often many connections, it is difficult to find a problem or check that all of the connections are correct when cables are moved or replaced.
The corresponding lines from the active and standby cards are hooked to the intended node, bay, and line on the far end. At a customer site, the problem often becomes compounded when many of the nodes do not exist in the same Central Office (or other location) and traverse through patch panels.
There are currently some layer 3 (network) and layer 4 (transport) protocols that provide peer node information, however, these all have limitations. One such protocol is ILMI (Interim Local Management Interface). ILMI allows management information to be exchanged between management entities within peers. The information is exchanged over a direct encapsulation of SNMP (Simple Network Management Protocol). ILMI, however, needs to be enabled at both ends. Also, the end points of ILMI need not be adjacent next hop nodes. ILMI also requires preset configurations on the nodes. PNNI (Private Network-to-Network Interface) is a suite of network protocols that can be used to discover an ATM network topology, create a database of topology information, and route calls over the discovered topology. PNNI has limitations similar to those described above for ILMI. Furthermore, neither of these protocols is able to run on standby cards. For example, when 1+1 APS is provisioned in card redundancy, the same data is propagated on the lines connected to the active and standby cards. Thus, protocols such as PNNI or ILMI are not useful in determining the neighbor information for the standby card.
Accordingly, there is a need for a method and system for easily determining where a given cable is connected to identify the peer node and other connection information.